ABOUT THIS PROSPECTUS SUPPLEMENT
On July 14, 2020, we, as a well-known seasoned issuer as defined in Rule 405 under the Securities Act of 1933, as amended,
filed with the Securities and Exchange Commission (SEC) an automatic registration statement on Form S-3, which registration statement became automatically effective upon filing. Under
this shelf registration process, we may, from time to time, sell common stock and other securities, of which this offering is a part.
This document is part of the automatic shelf registration statement that we filed with the SEC and consists of two parts. The first part is
this prospectus supplement, including the documents incorporated by reference, which describes the specific terms of this offering. The second part, the accompanying prospectus, including the documents incorporated by reference, gives more general
information, some of which may not apply to this offering. Generally, when we refer to the prospectus, we are referring to both parts combined. This prospectus supplement may add to, update or change information in the accompanying
prospectus and the documents incorporated by reference into this prospectus supplement or the accompanying prospectus.
If information in
this prospectus supplement is inconsistent with the accompanying prospectus or with any document incorporated by reference that was filed with the SEC before the date of this prospectus supplement, you should rely on this prospectus supplement.
Neither we nor the selling shareholder nor the underwriters have authorized anyone to provide any information or to make any representations other than those contained in this prospectus supplement or in any free writing prospectuses we have
prepared. This prospectus supplement, the accompanying prospectus and the documents incorporated by reference into each include important information about us, the selling shareholder, the securities being offered and other information you should
know before investing in our securities. You should also read and consider information in the documents we have referred you to in the sections of this prospectus supplement entitled Where You Can Find More Information and
Incorporation by Reference and in the sections of the accompanying prospectus entitled Where You Can Find More Information and Incorporation of Certain Information by Reference.
We further note that the representations, warranties and covenants made by us and the selling shareholder in any agreement that is filed as an
exhibit to any document that is incorporated by reference herein were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be
deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as
accurately representing the current state of our affairs.
Neither we nor the selling shareholder take responsibility for, and can provide
no assurances as to the reliability of, any information that is in addition to or different from that contained or incorporated by reference in this prospectus supplement and the accompanying prospectus. Neither we nor the selling shareholder are
offering to sell these securities in any jurisdiction where the offer or sale is not permitted. You should not assume that the information contained or incorporated by reference in this prospectus supplement or the accompanying prospectus is
accurate as of any date other than as of the date of this prospectus supplement or the accompanying prospectus, as the case may be, or in the case of the documents incorporated by reference, the date of such documents regardless of the time of
delivery of this prospectus supplement and the accompanying prospectus or any sale of our securities. Our business, financial condition, liquidity, results of operations and prospects may have changed since those dates.
Unless otherwise stated, when used in this prospectus supplement or the accompanying prospectus, the terms Adaptive,
we, our and us refer to Adaptive Biotechnologies Corporation, a Washington corporation, unless otherwise specified or the context otherwise requires. Adaptive and all product candidate names are our
common law trademarks. This prospectus supplement, the accompanying prospectus and the information incorporated by reference herein and therein contains additional trade names, trademarks and service
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